This patent is directed to a detector and method for detecting when a vessel is proximate to a surgical instrument or tool, and in particular to a detector and method using the emission and detection of light (such as visible and/or near visible light) for detecting when one of a ureter, a bile duct or a lymphatic vessel is proximate to a surgical instrument or tool.
The identification of artifacts, and in particular vessels, during surgical procedures can provide valuable information for the surgeon or surgical team. For instance, identification of a blood vessel from a vessel that carries a fluid other than blood may permit the non-blood carrying vessel to be avoided, minimizing the chances of injury to the non-blood carrying vessel. Alternatively, identification of the blood vessels and the non-blood carrying vessels may permit the non-blood carrying vessel to be isolated, instead of avoided.
In regard to identification of the vessel to avoid injury, consider the opportunity for iatrogenic ureteral injury during gynecological, urological and other pelvic region surgeries. Such an injury may occur as a consequence of the surgical procedure. Additionally, because the ureters course close to major blood vessels, such as the uterine arteries, ureteral injury can occur as a consequence of attempts to control bleeding. In particular, when inadvertent intraoperative bleeding obstructs the surgeon's field of view, the surgeon's attempts to control the bleeding by cauterizing, clamping or suturing the blood vessels can lead instead to ureteral injury.
Given the proximity of major blood vessels to the ureters and the obstruction of the surgeon's field of view should bleeding occur, injuries can occur even when the surgeon has a sound understanding of normal anatomy. Aberrant ureteral anatomy occurs in up to 8% of the population, however. When combined with the other factors, the surgeon faces a considerable challenge.
A systematic review of gynecological procedures has determined that ureteral injury occurs in 0.03% to 2.0% of abdominal hysterectomies, 0.02% to 0.5% of vaginal hysterectomies and 0.2% to 6.0% of laparoscopic-assisted vaginal hysterectomies. Considering the factors addressed above, perhaps these figures are not surprising. Because of the physiological importance of the renal system and the significant negative consequences of injury to the same, these rates are particularly sobering.
Ureteral injury can lead to ureteral obstruction (for example, if the ureter is ligated) or discontinuity (if the ureter is resected). If an injury to the ureter has occurred and is unrecognized (for example, if the ureter is crushed), it may lead to the formation of fistulas in addition to obstruction. Certainly, ureteral injury can lead to significant patient morbidity and mortality. In any event, ureter injury will increase the likelihood of hospitalization (if the procedure is performed on an outpatient basis), as well as the duration of the hospital stay.
Also in regard to identification of a vessel to avoid its injury, consider the treatment of gallstone development through surgical intervention, which is quite common in the United States with approximately 400,000 cholecystectomies performed annually. One important complication of these procedures is bile duct injury. The bile duct, which carries bile from the liver to the intestines, is disposed in close proximity to the gallbladder. Furthermore, the bile duct is buried under fatty tissue that may prevent the surgeon from directly visualizing the duct.
The estimated incidence of bile duct injury in laparoscopic cholecystectomies (which account for nearly 90% of all cholecystectomies performed in the United States) is between 0.3 to 2.7%. Again, because of the importance of the bile system and the significant negative consequences of injury, this rate is significant.
Mild injuries to the bile duct may include cystic duct leakage and bile duct strictures. Major injuries include more significant amounts of leakage and even complete transection of the common bile duct itself. Leakage of bile into the peritoneum can lead to a painful and potentially dangerous infection. While mild injuries may be treated endoscopically and/or interventionally, major injuries often require open surgery, such as hepaticojejunostomy. Thus, injuries to the bile duct (especially major injuries that may require open surgery) may increase the duration of the hospital stay and the length of the time for the patient to return to full activity after the procedure.
In regard to identification of the vessel to facilitate its isolation, sentinel lymph biopsy (SLNB) has been increasingly used while staging lymph node metastasis. Breast cancer, melanoma and gastrointestinal cancer malignancies have all been successfully staged using SLNB. SLNB provides accurate staging information with less morbidity than the previous widely-accepted technique of formal surgical dissection of the draining lymph node basin. However, SNLB requires proper identification of the sentinel lymph node.
As set forth in more detail below, the present disclosure describes a surgical system including a vessel detector and method of detecting a vessel embodying advantageous alternatives to the existing methods, which may provide for improved identification for avoidance or isolation of the vessel.